21222112424 has 16 divisors (see below), whose sum is σ = 39852972000. Its totient is φ = 10594653232.

The previous prime is 21222112421. The next prime is 21222112477. The reversal of 21222112424 is 42421122212.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21222112424.

It is not an unprimeable number, because it can be changed into a prime (21222112421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2044874 + ... + 2055225.

It is an arithmetic number, because the mean of its divisors is an integer number (2490810750).

Almost surely, 2^21222112424 is an apocalyptic number.

It is an amenable number.

21222112424 is a deficient number, since it is larger than the sum of its proper divisors (18630859576).

21222112424 is a wasteful number, since it uses less digits than its factorization.

21222112424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4100752 (or 4100748 counting only the distinct ones).

The product of its digits is 1024, while the sum is 23.

Adding to 21222112424 its reverse (42421122212), we get a palindrome (63643234636).

The spelling of 21222112424 in words is "twenty-one billion, two hundred twenty-two million, one hundred twelve thousand, four hundred twenty-four".